Many people are suffering from the repetitive strain injury known as carpal tunnel syndrome. Carpal tunnel syndrome is a condition caused by compression of a nerve in the wrist, and it can cause pain, tingling, numbness, and weakness in the arms, wrists, hand and fingers. A similar condition — tarsal tunnel syndrome — can affect the ankles and feet.
The cause of carpal or tarsal tunnel syndrome is often injury or inflammation due to overuse. With carpal tunnel, we tend to think of too much computer use, or working on an assembly line, as common triggers. In addition to repetitive use, ankle trauma (such as a fracture), very flat feet, and cysts can contribute to tarsal tunnel syndrome.
But for a percentage of sufferers, the inflammation and swelling in the tendon and nerve areas of the arms or legs have nothing to do with overuse or structural problems. Instead, the inflammation and resulting nerve entrapment are due to undiagnosed, untreated — or even diagnosed but improperly treated — hypothyroidism.
Because these conditions are common and can affect your ability to work and function in your daily life, it’s important to not only recognize the symptoms and take them seriously, but to know the potential role of a thyroid dysfunction.
In carpal tunnel syndrome, the median nerve — a nerve that runs from your forearm to your hand — gets compressed at the wrist. This compression affects the feeling in your hand, wrist, thumb and fingers. Common carpal tunnel syndrome symptoms include:
Weakness in the hand and fingers
Pain or numbness in the hand, wrist, and arm
Burning, tingling or itching in the palm and fingers — in particular, the thumb and index finger.
Difficulty forming a fist
Difficulty picking up objects with your hand
Difficulty holding heavier items in your hand
In tarsal tunnel syndrome, the nerve that becomes compressed is the tibial nerve. This nerve runs down the back of the leg, to the ankle. Common symptoms include pain, burning and tingling on the sole of the foot.
Surgery is often recommended as a treatment for these conditions. But surgery can have side effects, a longer recovery time, and may not even resolve the condition. Given the prevalence of undiagnosed hypothyroidism — some experts estimate that as many as 30 million or more Americans have an underactive thyroid and don’t know it — a comprehensive thyroid evaluation should be a first step for anyone with carpal or tarsal tunnel syndrome symptoms.
A comprehensive evaluation should include a thorough family and personal history, and a clinical exam that tests your Achilles reflex, measures heart rate and blood pressure, palpates your neck and thyroid area, and observes other clinical symptoms such as loss of eyebrow hair, or facial swelling.
Blood tests, including TSH, Free T4, Free T3, and thyroid antibodies, can help round out the picture of thyroid function and enable a practitioner to make a diagnosis.
If you are already diagnosed with hypothyroidism, and are experiencing carpal or tarsal tunnel syndrome, you’ll definitely want to make sure your treatment is optimized, to ensure that your thyroid condition is not contributing to the development or worsening of symptoms.
If you are newly diagnosed with hypothyroidism, proper treatment with prescription thyroid hormone replacement drugs may be all you need to resolve your carpal or tarsal tunnel syndrome. While the thyroid is normalizing, however, a variety of less invasive approaches may help speed recovery and help relieve discomfort.
Some of these treatments can include:
Rest of the affected area
A wrist splint
Arch supports or custom orthotics for shoes
Stretching and strengthening exercises
Nonsteroidal anti-inflammatory drugs, such as aspirin, ibuprofen, and nonprescription pain relievers to reduce inflammation and pain
Orally administered diuretics (“water pills”) to decrease swelling
Corticosteroids (such as prednisone) or the drug lidocaine (an anesthetic) can be injected directly into the affected area, or in some cases taken orally, to help relieve pressure on the nerve and help relieve symptoms
Some studies show that vitamin B6 (pyridoxine) supplements may ease the symptoms of carpal tunnel syndrome.
Mary Shomon is an internationally-known thyroid patient advocate, and is author of a number of best-selling health books, including Living Well With Hypothyroidism and The Thyroid Diet. Since 1997, she has run the Internet’s most popular thyroid patient sites: About.com Thyroid Site and Thyroid-Info.com.